After finishing neoadjuvant chemotherapy and surgery, some people are told that the pathology report shows no remaining cancer cells. It is a huge relief, yet it can also stir up worry: even though the result looks good, what if hidden cells are left behind and grow again? Many then ask whether they can receive preventive chemotherapy or immunotherapy even when no cancer is found. That is a very understandable feeling.
When the removed tissue is examined under a microscope and no cancer cells remain, this is called a pathologic complete response, often recorded as something like ypT0N0. It is considered a favorable sign that the pre-surgery treatment worked well. However, a complete response does not guarantee that the cancer will never return, which is why regular follow-up (surveillance) testing is still needed.
Treatment given after surgery is called adjuvant therapy. Its goal is to target microscopic cancer cells that scans cannot detect. But whether to give it is not decided simply because a patient wishes for it. Doctors weigh how high the remaining risk (residual risk) is against the burden of side effects, guided by evidence built up from clinical studies.
Importantly, immunotherapy is not free of side effects. Because it works by boosting the body's immune system, it can cause immune-related adverse events in the thyroid, liver, lungs, bowel, skin and elsewhere, and some can last even after treatment ends. Adding a treatment whose benefit is unclear, just to do something because you are anxious, may bring more harm than good.
When a pathologic complete response is confirmed, the benefit of extra adjuvant treatment is often not clear-cut, so careful follow-up is frequently the preferred path. In contrast, when cancer remains in the tissue or risk factors are high, adjuvant treatment may be recommended. The right answer depends on individual factors — initial stage, history of lymph node spread, pathology results and biomarkers — so someone else receiving it does not mean it fits you.
It helps to bring your questions to your medical oncology visit. For example, you might ask whether there is evidence supporting adjuvant immunotherapy in your specific situation (a complete response), whether surveillance rather than treatment is the current standard for you, how NGS or biomarker testing may guide future choices, and — if treatment is advised — what the coverage and side effects would be. Anxiety is completely understandable, but it is worth remembering that more treatment does not always mean a better outcome.
This article is for general information only and does not replace the diagnosis or care of an individual patient. Please discuss any decisions about treatment with your own medical team.